Flour sifter



March 5, 1929. w, ANDREWS I 1,704,525

FLOUR SIFTER Filed Aug. 4, 1928 side thereof.

Patented Mar. 5, 1929;

stares! mas-25 ALFRED W, AN'DREVJS, ROCKFORD, ILLINOISI, ASSIGNOR' T0 ADAM GSCHWINDT, OF

- ROCKFORD, ILLINOIS.

FLOUR SIFTER.

Application filed August 4, 1928. Serial No, 297,409.

This invention relates to an improved flour sifter for domestic use.

The pr1nc1pal ob3ect of my mvention 1s to provide a flour sifter operating smoothly and easily and with such efficiency that flour and baking powder, or other materials put therein, are thoroughly sifted and admixed as well as thoroughly aerated in one handling thereof.

I attribute the eflicient operation of the device to several novel features, to wit :-'the provision of rotating agitators having struck up mixer or beater vanes which serve to mix the materials thoroughly as well as to beat the same sufficiently to cause aeration thereof; annular funnel-shaped deflectors cooperating with the rotating agitators to direct the materials onto the agitators and prevent the same from being crowded to the sices, and spring ten sioners serving to hold the agitators in close but yielding contact with the screens and thus insure the desired efficient cooperation therebetween. y

The invention embodies several other improvements going to make up a thoroughly practical device of sturdy design such as will not develop mechanical troubles in service, all of which, together with the foregoing, are fully described in the following specification in which reference is made to the accompanying drawing, wherein Figure 1 is a plan view of my improved flour Sifter;

Fig. 2 is a central vertical section taken on the line 22 of Fi g. 1 looking in the direction of the arrows; and

Fig. 3 is a transverse sectional detail taken on the line 3-3 of F g. 2 looking in the direction indicated.

The same reference numerals are applied to corresponding parts in the three views.

The sifter comprises the usual type of sheet metal container 5 open at the top and bottom and provided with a suitable handle 6 at one A. hand crank 7 equipped with a suitable knob 8 extends from the container to the right of the handle 6, preferably at right angles t ereto. The crank 7., in accordance with my invention, isprcferably formed from single piece of wire square in cross section, having the shaft portion 9 thereof turning freely in round holes 10 proi ided at diametricallyopposed points in the walls of i the container. The squareness of the "Wire also does not interfere with the free turning of the knob 8 and is of advantage in facilitat ing'the assembling of the drive sprocket 11 to turn with the shaft, the hole 12 in said sprocket being square and of a size snugly, to receive the shaft. A stamped sheet metal hub 13 suitably spot-welded to the sprocket 11 at the rim thereof provides a bearing at 14: for the sprocket in spaced relation to the bearing 12 so that the sprocket is bound to reright angles and pierced to receive the shaft 9, the bent end being arranged to be soldered, welded, or otherwise suitably secured to the side wall of the container, and having the other end thereof bent downwardly as at 18, forwardly as at 19, and ,upwardly as at 20, portions 18 and 20 being pierced to receive the shaft 9 and the portion 20 bearing against theflat face of the sprocket 11 definitely to position the same and serve as a guide therefor in the operation thereof. The bracket 16 between the portions 17 and 18-has the lateral edges thereof bent down alongside the shaft 9, as at 21, to lend stiffness to the bracket. It will be evident that in assembling, the shaft 9 can be slipped through the parts described and that when the projecting end has a washer 22 slipped over the same and has prongs struck therefrom, as at 23, the crank'assembly is completed and will always operate satisfactorily.

The sprocket- 11 has a plurality of circumferentially spaced holes 24: punched therein to receive the teeth of a stamped sheet metal pinion 25 mounted on the upper end of a vertical shaft 26 which, like the shaft 9, is formed from a piece of square wire. The shaft 26, as will presently appear, transmits the drive to the series of rotary agitators 27 cooperating with the stationary screens or sieves 28. The portion 19 of the bracket 16 is pierced to receive the upper end of the ment. Another bracket 18' disposed at right angles to the bracket 16 cooperates with the latter to form a rigid support for the upper end of the shaft 26.,1t being evident that )arts bein bent out of sha )e in the assemblin thereof in tne sifter. Eacha 'itator is shown as having siX spokes, although, of

the bracket 16 serves in the nature of a cross-brace assuming the lateral thrust imposed on the bracket 16 in the driving of the pinion 25 by the sprocket 11. If the bracketl6 were not provided a strain would be placed on the soldered or welded connection of the portionli of the bracket 16 with theside wall of the container. The bracket 16 has the 'one endthereof bent downwardly as at 17, and soldered, welded, or otherwise suitably vsecured to the side wall of the container 5, the other end of the bracket being bent downwardly as at 18 and forwardly as at 19, and the portion 1?)" being pierced to provide a bearing for the upper end of the shaft26. The portion 19of the bracket 16,

it will be observed underlies the portion19 of the bracket 16 and bears against the top of the pinion 25 serving, like the portion 20 course, any number might be provided and I prefer to provide on one edge of-every alternate spoke a mixing or beating vane 41 projecting from'the plane of the agitator preferably at an acute angle with respect thereto. The inclination of the vanes 41 is to the rear as respects the direction of rotation of the agitators, the latter being arranged to turn in a clockwise direction as viewed in Figv 1, The several agitators are assei bled on the shaft 26 in such a way that the vanes 41 are disposed in staggered relation ship; that is to say, the vanes 4i on the intermediate agitator are offset with respect to the vanes of the upper and lower agitators. The purpose in this is to make certain of thorough mixing as well as heating oftlie materials passed through the sifter. It will I be evident that in the rotation of the agitaof the bracket 16, as a guide for the pinion insuring that the same will run true in the operation thereof by the sprocket 11. The bracket 16 between the portions 17, and 18 has the lateral ecges thereof bent downwardly, as indicated at 21, to reenforce the bracket and minimize the likelihood of its buckling;

The screens or sieves 28 have the raw edges thereof clinched in rolled sheet metal circuilar frames 30 and the centers thereof have openings in which'grommets 31 are inserted, the said grommets permitting the insertion therethrough of the shaft 26 and the turning of the shaft with respect to the screens. The walls of the container 5, have annular beads formed therein, as indicated at" 32. These beads provide annular shoulders within the container against the under side of which the frames 30 of the screens are ar ranged toengage when the screens are assembled in the container in a manner present I to be described the frames bein arranged to be soldered, or otherwise suitably secured, 'to'the-walls out the container to hold the same against downward displacement Cooperate,

annular beads 39 and 40 formed in' the hub- 35 andrim ild'respectively,thus serving to lend considerable reenforceinent to the agitators and minimize the likelihood of these tors with respect to the screens the spokes 3'? will sweep the screens and thereby help to work the material therethrough by thorough agitation thereof and that the vanes 41 will, at the same'time, function to thoroughly admin whatever constituents are in the material as, for example, flour and baking powder, r flour and sugar. The vanes 4lalso beat the materials sulhciently to aerate the same so that the materials discharged from the sifter are found to be light and fluffy and of line even texture. Coiled compression springs 42'are provided yieldingly to urge the agitators toward the screens to insure the efficient cooperation therebetween. All of the springs 42 are held in place on the shaft 26, the uppermost spring being disposed betweenthe upper agitator and the under side of the pinion 25, whereas the other springs extend between the grommets 31 and the agitators the:ebeneath. The uppermost spring 42, therefore, cooperates with the portion 19 of the bracket 16 in maintaining the pinion 25 in proper intermeshing relation with the sprocket 11. y

The operation of the agitators has a tend ency to crowd the materials to the sides of the container. This, however, is not a characteristic peculiar to the present sifter inasmuch as it is well known that flour siit'ters generally have to be shaken or struck now a d then in the course of the sifting to disloc o the flour from the sides where it tends to col lect. To remedy this difficulty I provide funnel-shaped deflectors 43 above the agitators to concentrate the materials where they will be subjected to the full play of the agitatr and the ll'lllrlllg beating vanes pror .ed thereon. The uppermost deflector 43 has the upper edge thereof located beneath one of the annular beads 32 and soldered, welded, or otherwise suitably securedto the wall of the contaner, the other deflectors having the up per edges thereof located beneath thefframes 30 of the screens QSand likewise soldered, welded, or otherwise suitably secured, to the walls of the container. The lower edges of the deflectors 43, it will be observed, are dis posed directly over the annular beads 40 of the rims 36 of the agitators, thus preventing the flour or other material from ;;etting behind the deflectors. It is found that the deflectors make it unnec zssary to shake or strike the Sifter during the operation. thereof inasmuch as it is absolutely impossible for the material to crowd to the sides of the corn tainer beyond the range of the agitators.

The cor traction obviously very simple and economical to iminufacture. There is, furthermore, no difficulty in assembling; once the crank assembly and its bracing brackets 16 and 16 are assembled in the container, the other parts can be dropped into place one after another and the deflectors i3 and screen frames 30 soldered or welded in place, the container being inverted in the latter part of the assembling operation to facilitate matters.

It is believed the foregoing description conveys a clear understanding of my inventherein and an agitator having parts sweep in the sieves and having the upper end of the shaft thereof equipped with a pinion for turning the same, of a shaft for operating the agitator passing diametrically through the container for support in the opposite side walls thereof and having a hand crank at one end outside the container and a sprocket inside the container meshing with the pinion on the agitator, a bracket secured at one end to the container wall and extending inwardly along the shaft, the inner end having the shaft passing therethrough and providing a depending portion having the upper end of the agitator shaft bearing therein for sup port, and a cross-brace for said bracket eX- tending transversely with respect thereto between the depending portion of said bracket and the side wall ofthe container.

2. In a flour sifter, thecombination'with a container having one or more sieves mounted therein and an agitator having p rts sweeping the sieves and having the upper end of r the shaftthereof equipped with a pinion for turnin'gthe same, of a shaft for operating the agitator passing diametrically through the container forsupport in the opposite side walls thereof and having a hand crank at one end outside the container and a sprocket inside'the container meshing with the pinion on the agitator, a bracket secured at one endto the container wall and extending inwardly along the shaft, the inner end having the'shaft )assin therethrou 'h and rovldln a de- D b p O pending portion hav ng the upper end of the agitator shaft bearing therein for support and another portion bearing against one side of the sprocket on the crank shaft to maintain the same in proper-intermeshing relation with the pinion, and another bracket disposed in transverse relation to the last mentioned bracket secured at one end to the container wall and extending inwardly tothe inner end of the other bracket, the inner end having the upper end of the agitator shaft bearing there in for support, and said inner end portion also bearing against one side of the pinion on the agitator shaft wherebyto maintain the same in proper intermeshing relation with the sprocket on the crank shaft.

3. In a flour sifter, the combination with a container having one or more sieves mounted therein and an agitator having parts sweeping the sieves and having the upper end of the ing the, same, of a shaft for operating the agishaft thereof equipped with a pinion for turn tator passingdiametrically through the con tainer for support in the opposite side walls thereof and having a hand crank at one'cnd outside thecontainer and a sprocket inside the container meshingwith the pinion on the agitator, a bracket secured at one end to the container wall and extending inwardly parah lel with the crank shaft, the inner end having the upper end of the agitator shaft bearing therein for support, and another bracket disposed'in transverse relation to the inner of the first bracket, the one end of said bracket being secured to the container wall and the inner end thereof also'having the upper end of the agitator shaft bearing therein for support- 7 I p 4. In a, flour Sifter, the combination with a container having one or more sieves mounted therein and an agitator havingparts sweeping the sieves and having the upper end of the shaft thereof equipped with a pinion for turnin the same of a shaft for 0 eratin the a itator passing'diametrically through the con.

tainer wall and extending. inwardly parallel with the crank shaft, the innercnd having the,

upper end of the agitator shaft bearing therein for support, and another'bracket disposed 1n transverse relationto the inner end of the secured to the container wall and the-inner end thereof also having the upper end of the agitator shaft bearing" therein for support,

b a sifting screen, an agitator cooperating one of said brackets ha a portion bearing against the s1de of the sprocket on the crank shaft to maintain the same in proper intermeshing relation with the pinion on the agitator shaft, and one of the brackets also having a portion bearing against one side of the pin- 7 ion onthe agitator shaft to maintain the'saine in proper intermeshing' re ation with the sprocket on the crank shaft.

. 5. In a device as set forth in claim at where in the crank shaft is square in cross-section and has a shoulder thereon spacedwith respect to the portion of the first bracket bearing against theside of the sprocket, the said sprocket comprising a stamped sheet metal blank having a center hole to fit the shaft, and a dished hub member of stamped sheet metal also having the rim portion thereof secured to the aforesaid blank, at least one of said center holes being square to provide a driving connection between the sprocket and the shaft, and the said center holes being sufhcientiy spaced by reason of the construct ion described to provide ample bearing support for the sprocket on the shaft.

6. In a device as set forth in claim 4: wherein the crank shaft has a shoulder spaced from the portion of the first menti bracket bearing against the side of 7 sprocket, the said sprocket comprising a blank struck from sheet metal and having a center hole provided therein and a stamped sheet metal hub member of dished form also having a center hole therein and having the rim port for the sprocket on the shaft.

7 A sifter of the character described com prising, in combination, a contalner 'llEtVl therewith having the upper end of the shaft thereof equipped with a pinion, a shaft passing diametrically through the container above the agitator having a hand crank at one end outside the container and a sprocket inside the container meshing with the pinion, abracket formed of a strip of sheet metal secured at one end to the container wall and bent to extend inwardly along the crank shaft and thence downwardly to provide bearing support for the upper end of the agitator shaft and thence upwardly and having a bearing on the crank shaft alongside the sprocket thereon, and another bracket formed 'of a strip of sheet metal secured at one end to the container wall and bent to extend inwardly transversely WltlllfiSPGCtilO the inner Jil e110]. (3011 first bracket so as to cooperate with the latter in. providing bearing support for they upper end of the agitator shaft the downwardly bent portion of the second bracketbeing disposed preferably agitator shaft.

In a sifter of the character described, the combination with a container having one 01' acre sieves mounted therein, an agitator havparts sweeping the sieves and havingthe' up end of the shaft thereof equipped with a pinionfor turning the same. and a shaft for operating the agitator passing diametrically throu the container for support in the opposite side walls thereof and having a hand crank at one end outside the container, of a sprocket meshing with thepinion for transmitting the drive from the crank shaft to the ag'tator shaft, said. sprocket comprising a blank struck from sheet metal and'having a alongside the pinion on the center hole provided therein to receive the shaft and a stamped sheet metal hub of dished form having a center hole provided therein concentric with but spaced from the other center hole to receive the shaft and having the rimportion thereof secured to the aforesaid blanln, said sproc :et having a drivi no; connection with said shaft, and means for h olding said sprocket against movement with respect to theshaft endwise of the latter.

9. A device as set forth in claim 8 wherein the shaft in square in cross-section and wherein at least one of the center holes referred to are of corresponding form to provide the driving connection between the shaft andthe sprocket without the mediumof other means or without the necessity of welding or otherwise securing the'sprocket to the shaft.

Y 10. in a sifter of thecharacter described, the combination with a container having one or more sieves mounted therein and an agitator having parts sweeping the sieves and having the upper end of the shaft thereof equipped with a pinion for turning the same, of a shaft for operating the agitator passing diametrically through the container for hearin support in the opposite side walls thereof said shaft being formed of a single piece,

of wire square in cross-section and having one end thereof bent to provide a hand crank out, side the contalner, a sprocket having a square center hole for reception of said shaft and to one or more sieves therein, an agitator having parts sweeping the sieves and having means for turning the same, and one or more deflectors at the side Walls of said container for preventing accumulation of material otherwise crowded to the side walls in the operation of the agitator.

12. A sitter ot the character described comprising in combination, a container having one or more sieves therein, an agitator having parts sweeping the sieves and having means for turning the same, and one or more substantially tunnel-shaped deflectors disposed above the sieves about the sides of the container with the smaller ends thereof cisposed over the parts of the agitator sweeping the sieves.

13. A sitter of the character described comprising in combination, a containerhaving one or more sieves therein, an agitator havin arts swee aim the sieves and havin D D 23 means for turning the same, and means on the walls of said'container servin to prevent b the accumulation of material in the space be 0nd the ran e of o eration of the swee mg agitator parts.

14:. A sitter ot the character described comprising in combination, a container having one or more sieves therein, an agitator having parts sweeping the sieves and having means for turning the same, and tunnelshaped sheet metal rings disposed above the sieves with the smaller ends thereof lowermost and just within the range of operation of the sweeping parts ot the agitator, the to 15. A sitter of the character described comprising in combination, a container having one or more sieves therein, an agitator having parts sweeping the sieves and having means for turning the same, and one or more substantially funnel-shaped deflectors disposed above the sieves about the sides elf the container with the smaller ends thereof disposedover the parts of the agitator sweeping the sieves, the said agitator parts having upwardly projecting mixing or beating vanes provided thereon operating in the Plane of the deflectors nearest the smaller ends thereficientoperation.

of to which point the material is concentrated in operation.

16. In a sitter, the combination of, a con-' tainer having one ormore sieves mounted therein, and an agitator having portions all disposed substantially in one plane close to the surface or" the sieve to sweep the same and having mining or beating vanes projecting upwardly from the plane of the sweeping portions at an acute angle, the inclination of said vanes being to the rear as respects the direction oft-rotation ot'the agitator. i p

17. In a sittenthe combination of a container having one or more sieves mounted therein, and an agitator stamped from, sheet metal to provide aflat hub portion and a flat concentric rim portion joined by spokes all disposed in substantially one plane for operation close to the surface of the sieve to sweep the same in the rotation thereof, certain of the spokes having vanes provided thereon projecting upwardly at an acute angle to the aforesaid plane, the inclination of said vanes being to the rear as respects the direction of rotation of the agitator. V

18. A device as set forth in claim'l? wherein the sheet metal agitator has reento be rotated to sweep the same, a Slllfi'rGX tending through the screens and intercon-v necting the agitators for operation in unison,

means for rotating said shaft, and coiled compression springs mounted on the shaft and bearing against the agitators yi'eldingly to urge the same toward the screens for at In witness of the foregoing I athx my signature. a H t ALFRED W. ANDREWS. 

